Canon 450d versus 40D .

[Stevelphoto]

Do the images produced by both cameras at a given shutter speed appear to be exposed correctly? (I.e. are they both as bright or dark as one another?)

[Jason Claxton]

Thanks for the reply Steve
I didn't compare that today,I'll take another look next time the cameras together.I guess you have an idea as to what is going on here then?Its beyond me at the moment

I'll get back to you on that asap.Jason

[Stevelphoto]

Hi Jason,

If both cameras are producing images that appear to be correctly exposed, but give a significantly different reading in terms of shutter speed for the same subject, then something seems to be amiss.

I should make it clear that I'm certainly not an expert on the inner workings of a camera, but to my mind, this isn't making sense; if the same amount of light is hitting camera sensors of the same size (although admittedly different amounts of pixels, which, given that there will be some light loss between pixels, could give a slight difference) set to the same ISO setting through a lens set to the same aperture and the cameras calculate a different shutter speed, it seems technically impossible to me that the images that are consequently produced can both be exposed properly.

So, if this is true, then I think a setting must be being overlooked, or there is something wrong with one of the cameras. Even then, with the latter situation, I can't see how a camera can have a metering fault, yet produce a correctly exposed image.

Is there any chance of posting any of the pictures you took - either on the 40d, 450d or both - with EXIF data attached?

Cheers,
Steve.

[Jason Claxton]

Thanks for staying with this Steve,even EXIF data is knew to me,I will look that one up and see what I can do.I can't compare cameras until this weekend though.But in the mean time I'll keep checking settings.Wouldn't reverting the camera to default settings iron out any settings problems?Sorry I've only been into cameras a few months.


Cheers Jason.

[Stevelphoto]

Hi Jason,

No problem. I should have explained what EXIF is; it's basically data attached to an image that shows us what shutter speed, aperture, ISO, metering mode etc the camera was set to when taking the picture.
There should be an option to preserve it when saving after processing or resizing an image.

Reverting to default settings could help - what dial mode to you use currently? I would recommend using Av, Tv or Manual when comparing the two cameras, otherwise the comparison will not be valid (when using auto, it will be hard to keep all other settings between the two cameras constant, as the camera automatically chooses almost all the settings).

If you can post an image with EXIF (especially from both cameras), it may help determine where things might be going wrong.

Cheers,
Steve.

[Jason Claxton]

Cheers for the info Steve.Both of us use Av,my manual mentions reverting back to original settings in M(manual exposure)I'll work on getting some images with EXIF data on in.I don't use any photo editing at all,only compressing files for WAB with windows.

Thanks again.Jason.

[Stevelphoto]

That's OK Jason.
I can recommend Photofiltre as a very simple photo application. It's free, pretty fast and is easy to use.
When saving an image in photofiltre it gives you the option to keep or discard EXIF data (whereas some programmes automatically discard it), and allows you to select the level of compression via a slider.
It's definitely worth a try either way.

Cheers,
Steve.

[Jason Claxton]

Cheers for that Steve ,I've downloaded it now,...right I'll just work it out for a bit.Jason